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<head><meta charset="utf-8"><title>split generic member access RFC? · t-libs · Zulip Chat Archive</title></head>
<h2>Stream: <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/index.html">t-libs</a></h2>
<h3>Topic: <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/split.20generic.20member.20access.20RFC.3F.html">split generic member access RFC?</a></h3>

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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/split%20generic%20member%20access%20RFC%3F/near/234248629" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jane Lusby <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/split.20generic.20member.20access.20RFC.3F.html#234248629">(Apr 13 2021 at 00:03)</a>:</h4>
<p>So I'm pushing to clean up the generic member access RFC and part of it is updating to use the type tagged downcasting approach used in <a href="https://docs.rs/dyno">https://docs.rs/dyno</a></p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/split%20generic%20member%20access%20RFC%3F/near/234248761" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jane Lusby <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/split.20generic.20member.20access.20RFC.3F.html#234248761">(Apr 13 2021 at 00:04)</a>:</h4>
<p>part of the motivation for this change is to support a feature request made in the comments on the PR to make the <code>Request</code> machinery useful to the executors effort</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/split%20generic%20member%20access%20RFC%3F/near/234248784" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jane Lusby <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/split.20generic.20member.20access.20RFC.3F.html#234248784">(Apr 13 2021 at 00:04)</a>:</h4>
<p><a href="https://github.com/rust-lang/rfcs/pull/2895#issuecomment-736683549">https://github.com/rust-lang/rfcs/pull/2895#issuecomment-736683549</a></p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/split%20generic%20member%20access%20RFC%3F/near/234248975" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jane Lusby <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/split.20generic.20member.20access.20RFC.3F.html#234248975">(Apr 13 2021 at 00:06)</a>:</h4>
<p>I'm wondering if its still appropriate to have this be part of the generic member access RFC or if it warrants collaborating with the authors of the proposals alluded to from executors land and instead write up an RFC that focuses on bit that is shared</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/split%20generic%20member%20access%20RFC%3F/near/234249169" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jane Lusby <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/split.20generic.20member.20access.20RFC.3F.html#234249169">(Apr 13 2021 at 00:08)</a>:</h4>
<p>for now I'm leaning towards keeping it all together in one RFC to reduce the overhead, since most of the shared logic will not need to be exposed and stabilized as part of the generic member access RFC, but I'd like to know ahead of time if this is likely going to cause issues</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/split%20generic%20member%20access%20RFC%3F/near/234250018" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/split.20generic.20member.20access.20RFC.3F.html#234250018">(Apr 13 2021 at 00:20)</a>:</h4>
<p><span class="user-mention" data-user-id="220273">@Jane Lusby</span> So, FWIW, the last time libs looked at the RFC, it already felt <em>very</em> complex. Not necessarily more complex than it needs to, but complex.</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/split%20generic%20member%20access%20RFC%3F/near/234250048" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/split.20generic.20member.20access.20RFC.3F.html#234250048">(Apr 13 2021 at 00:21)</a>:</h4>
<p>I don't think combining more things into the same RFC will make it easier.</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/split%20generic%20member%20access%20RFC%3F/near/234250064" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/split.20generic.20member.20access.20RFC.3F.html#234250064">(Apr 13 2021 at 00:21)</a>:</h4>
<p>If anything, it'd be easier if there were straightforward subsets that could go in separately.</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/split%20generic%20member%20access%20RFC%3F/near/234250072" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jane Lusby <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/split.20generic.20member.20access.20RFC.3F.html#234250072">(Apr 13 2021 at 00:21)</a>:</h4>
<p>okay</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/split%20generic%20member%20access%20RFC%3F/near/234250148" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jane Lusby <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/split.20generic.20member.20access.20RFC.3F.html#234250148">(Apr 13 2021 at 00:22)</a>:</h4>
<p>let me see if I cant find the executors proposals then and start working on splitting our the downcasting logic into its own RFC</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/split%20generic%20member%20access%20RFC%3F/near/234250214" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/split.20generic.20member.20access.20RFC.3F.html#234250214">(Apr 13 2021 at 00:23)</a>:</h4>
<p>I also suspect that there may be value in walking through that RFC in detail, perhaps in a meeting, if we're going to make forward progress on it. I don't know what other <span class="user-group-mention" data-user-group-id="2645">@T-libs</span> folks think; does that seem like it'd help?</p>



<hr><p>Last updated: Aug 07 2021 at 22:04 UTC</p>
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